Means of transport with balancing construction comprising cylinders, and such a balancing construction

ABSTRACT

The present invention relates to a means of transport, comprising: a frame least two contact members, such as skis or wheels, which am oriented parallel to the direction of forward movement and which are arranged with clearance away from and toward the frame hereon; and a balancing construction between the frame and the contact members for the purpose of preventing slanting of the frame. The balancing construction can herein comprise per wheel at least one compartment filled with fluid and the compartments of at least two of the contact members can be in direct open mutual connection for the fluid.

[0001] The present invention relates to a means of transport, comprising a frame, at least two contact members which are oriented parallel to the direction of forward movement and which are arranged with clearance away from and toward the frame hereon. The known vehicles usually have a suspension between the frame and the contact members.

[0002] In the known means of transport it is usual for leaf springs, helical springs and so on to be used for the suspension. Known from DE-A-3.829.318 are means of transport designed as roller skates, skateboards etc., wherein use is made of hydraulic cylinders as suspension of the contact members designed as wheels relative to the frame. An separate, independent hydraulic suspension cylinder is applied per wheel. Similar configurations are also known from car engineering.

[0003] The means of transport with suspensions known from the above stated DE-A-3.829.318 have the drawback that as a result of the independent suspension per contact member the suspension of that contact member corresponds only with the free stroke of the cylinder used, optionally in combination with a source for fluid under pressure for the relevant suspension cylinder. An askew position of the means of transport, more particularly of the frame hereof, relative to the direction of forward movement or transversely relative thereto is thus an aspect resulting in low or inadequate comfort for the user during movement. In the case of for instance inline skates, which in the known art generally have no suspension at all or only a very inadequate one, the lack hereof or lack of adaptability to the road surface, particularly in the case of a very uneven road surface, results in a loss of control over the means of transport, which can result in very hazardous situations for the user.

[0004] A further drawback of the known means of transport with suspensions, to the extent that mechanical springs are applied herein, is the energy loss occurring therein. Such mechanical suspensions dissipate energy and the dissipated energy is lost, so that it cannot be used to increase the speed of movement.

[0005] The present invention has for its object to obviate or at least diminish the above stated drawbacks and problems of the known art, for which purpose a means of transport is provided according to the present invention which is distinguished by a balancing construction between the frame and the contact members for the purpose of preventing slanting of the frame, and that the balancing construction comprises per contact member at least one compartment filled with fluid under pressure and the compartments of at least two of the contact members are in open mutual connection for the fluid.

[0006] With a means of transport and a balancing construction for means of transport according to the present invention dissipation losses are minimized in that flow losses only occur for the fluid under pressure, which can be hydraulic or pneumatic. Due to the direct open connection with the compartments therebetween, an askew or oblique position of the frame, and therefore of the means of transport as a whole, is effectively prevented or compensated. User comfort is thus increased and, through good contact with the ground over which travel or displacement takes place, the grip thereon is improved whereby the control by the user of the means of transport, such as an inline skate, is increased.

[0007] It is noted that a car with a hydraulic suspension is known from French patent 989.134. The wheels of this car have a suspension, of which a hydraulic cylinder forms part. Such a suspension cannot however be deemed a balancing construction, since no balancing of the vehicle takes place in the sense that slanting is in no way prevented. Although the cylinders have connections, these are heavily damped connections which are not intended for transmitting the movement) of one of the wheels In opposing direction to another of the wheels. This is purely a spring suspension which happens to comprise hydraulic cylinders.

[0008] In a first preferred embodiment the contact members, the compartments of which are in open connection, lie in line. An oblique or askew position relative to the direction of forward movement is thus compensated or prevented inefficient manner. This is particularly the case for an embodiment with at least three inline contact members orientated parallel to the direction of forward movement, wherein the open connection between the compartments ensures that each of the contact members, irrespective of the course of the ground thereunder, remains within determined limits in contact with this ground. This is achieved by the direct open connection. The movement of one wheel to or from the frame is directly transmitted in uniform measure to the other wheels. Without a configuration according to the present invention an unevenness in the road surface over which travel is taking place would result in a displacement of the frame corresponding with the dimensions of the unevenness. According to the invention it is precisely the influence on the frame which is now reduced in inverse proportion to the number of wheels not influenced by the unevenness. Uneven surfaces in the ground over which travel is taking place are thus distributed over all contact members, so that these uneven surfaces have a considerably decreased effect on the frame, where the user can experience discomfort therefrom, without the contact members losing contact with the ground.

[0009] In an embodiment with at least three contact members in line, the invention has a further preferred embodiment, wherein the contact members are sub-divided into at least two sets of contact members, wherein the compartments of the contact members are in open mutual connection in each of the sets. The balancing characteristics per set of contact members as already described above are thus realized, which results in a design advantageous in its simplicity. It is further possible in such an embodiment to provide that the open connection of at least two of the sets are additionally connected. An embodiment is thus provided wherein all contact members lying in the line achieve an adjustment or compensation of the askew or oblique position relative to the direction of movement, wherein compensation first takes place per set, and only then via the additional connection of the sets. When such an additional connection between the sets is absent, an embodiment can be provided as an alternative, wherein in the compartments and the open connection of the separate sets of contact members different pressures prevail in the fluid under pressure therein. It is thus possible to take account of a load characteristic. The pressure on the front wheels of a car will therefore be generally higher than that on the rear wheels because of the location of the engine at the front of the car beneath the hood. Account can also be taken of the load characteristic as this occurs for instance in an inline skate. The middle and rear contact members herein experience a higher load relative to the direction of forward movement than the contact members at the front. By adjusting the pressure per set it is possible to take account of these load properties.

[0010] In a further preferred embodiment of the invention a means of transport has the feature that at least one of the contact members is arranged on the frame for tilting on a tilt axis lying transversely of the direction of forward movement, and the balancing construction of the relevant contact member comprises at least two compartments on either side of the tilt axis relative to the direction of forward movement. Such a tiltability of the contact members provides a further possibility for adjusting the mutual relative position of the contact members relative to the frame to unevenness in the road surface thereunder. Particularly if the two compartments of one contact member are here in open connection, the compartments of this contact member co-act after each tilting thereof in order to return the contact member to a non-tilted state of equilibrium. It is also possible in such an embodiment for at least two of the contact members to be arranged together on a sub-frame and for the sub-frame to be tiltable on the tilt axis. Such an embodiment is comparable to the above described embodiment, wherein the contact members are sub-divided into at least two sets.

[0011] When at least one of the contact members is tiltable, a means of transport according to the present invention can have the feature of a brake to be selectively energized, wherein at least one of the contact members energizes the brake when in tilted position relative to the direction of forward movement. The brake can herein be a simple brake block which can act on the running surface of the relevant tiltable contact member in the tilted state of this relevant contact member. In an embodiment wherein the tiltable contact member is the rearmost contact member of the means of transport in the direction of forward movement, a very effective brake for an inline skate is for instance provided. A user has only to lean back slightly, which is a natural reflex when he/she wishes to brake, in order to thus energize the brake. In this manner a very favourable embodiment of for instance inline skates is provided, which are notoriously dangerous in respect of the absence of an adequate brake function.

[0012] The means of transport can further be provided with at least one connection for feed or discharge of the fluid under pressure in order to selectively increase or decrease the height of the means of transport. The balancing characteristic of the means of transport can thus also be influenced herewith. Particularly in the case of non-motorized applications in which a hydraulic or pneumatic system may already be present, a user of such a non-motorized means of transport can thus adjust the balancing characteristic. Account can be taken herein of the experience and skill of a user, which is particularly favourable in the case of inline skates. When there is more fluid in the compartments, a more rigid suspension and/or a higher height of forward movement is provided. This latter is related to the chosen type of fluid, or even a combination of types, each with favourable properties. Particularly in the case of for instance trailers or other transport vehicles, it is possible for the purpose of loading and unloading thereof to lower the frame by removing fluid from the compartments. Fluid can be supplied when transport is resumed. This is even a possibility for trucks and the like.

[0013] In yet another preferred embodiment a means of transport according to the present invention has the feature that an elastically compressible body of for instance rubber is placed in at least one of the compartments or in the open direct connection. Such a body then provides more elastic properties to for instance per se very inelastic fluid, such as oil. This has the advantage that wheels of very hard material can be applied, which thus have a very low rolling resistance, while the comfort of the rider remains readily acceptable.

[0014] In addition to the above mentioned inline skates or roller skates in general, and cars, the present invention further relates to for instance wheelchairs, cross-country vehicles, trucks, caterpillar vehicles, boats such as speedboats and so on, and separately to a balancing construction for use in such a means of transport.

[0015] The present invention will be further elucidated hereinbelow on the basis of a description of preferred embodiments with reference to the annexed drawings, in which:

[0016]FIG. 1 shows a partly cut-away perspective view of a first embodiment of the means of transport according to the present invention; and

[0017]FIG. 2 shows a partly cut-away side view of a similar means of transport according to the present invention as in FIG. 1, but with some essential differences.

[0018] In the figures of separate embodiments of the present invention the same or similar parts and components are designated with the same reference numerals.

[0019] In FIG. 1 an inline skate 1 is shown as possible embodiment of a means of transport according to the present invention. It is noted that the present invention has many other embodiments, such as roller skates, wheelchairs, cars, cross-country, vehicles, trucks, boats and so on. It can be stated generally that the present invention embraces diverse types of vehicle wherein a balancing as described hereinbelow is important.

[0020] The inline skate in FIG. 1 comprises a shoe 2 mounted on a frame 3. Frame 3 is provided with brackets 4, between which contact members designed as wheels 5 are mounted with clearance in the direction which is upward in the figure. Wheels 5 are herein mounted in profiles 6, and profiles 6 are provided with pins 7 which protrude into slotted holes 8 arranged in brackets 4. Slotted holes e extend in the direction which is upward in the figure, so that wheels 5 together with profiles 6 have a clearance away from and toward frame 3.

[0021] Profiles 6 are U-shaped, wherein the legs of the U-shaped profiles 6 extend downward along wheels 5 and the body of U-shaped profile 6 is designed substantially horizontally in each case and extends some distance in the direction of forward movement.

[0022] Between the bodies of U-shaped profiles 6 and frame 3 are arranged two stops 9 for each body of U-shaped profiles 6, in side view in front of and behind the tilt axes defined by pin 7 and slotted hole 8 relative to the direction of forward movement. Profiles 6 with wheels 5 therein can thus tilt forward and backward on the tilt axes substantially defined by pins 7, as is clearly shown in the case of the second wheel 5 from the right in FIG. 1.

[0023] Stops 9 form or are connected to pistons in compartments designed as cylinders 10. Cylinders 10 are open on the side opposite pistons 9 and frame 3 is hollow and filled with fluid under pressure, such as hydraulic fluid. Alternatively, a pneumatic system can also be realized, wherein gas under pressure is applied instead of hydraulic fluid.

[0024] An expansion chamber 11, which can be functionally compared to an accumulator, is defined by a membrane 12 on the front side of the frame. In a manner comparable to an expansion tank in a heating system, the expansion chamber 11 is suitable for absorbing and damping abrupt pressure changes. For this purpose the expansion chamber 11 is filled with gas or fluid under an equal or lower pressure than that in the other part of hollow frame 3 in unloaded or lightly loaded state.

[0025] The space formed in hollow frame 3 forms an open connection, via which all cylinders 10 in the embodiment of FIG. 1 are in open connection with each other. The operation of such an embodiment of the present invention is as follows. When one of wheels 5 passes over an obstacle 13, the pins 7 move upward in slotted holes 8 in this relevant wheel 5, as is shown in the second wheel 5 from the right in FIG. 1. The hydraulic fluid is forced out of the two relevant cylinders 10 associated with the raised wheel 5. Because the interior of hollow frame 3 forms an open connection between all cylinders, the other wheels which are not impeded by obstacle 13 are pressed slightly downward under the influence of the hydraulic fluid in the hollow frame. The distance over which the wheels 5 not impeded by obstacle 13 are pressed downward, corresponds with the ratio between the number of wheels not per se depressed and the number of wheels 5 impeded by the obstacle. In the situation shown in FIG. 1, the second wheel from the right moves upward toward frame 3 over a distance corresponding with the height of obstacle 13 The other wheels are pressed downward over a quarter of this distance by displacement of fluids, since in the embodiment shown in FIG. 1 the upward displacement of the wheel impeded by obstacle 13 must be distributed over four wheels 5 not impeded by the obstacle. In this manner the obstruction caused by such an obstacle 13 to the whole frame, and therefore the whole inline skate 1, is limited to only a quarter of the height of the obstacle. In the case of six wheels the frame 3 with shoe 2 thereon is displaced over only a fifth part of the height of obstacle 13 when one of the wheels 5 passes thereover. It is found that with the present invention a balancing is provided which comprises profiles 6, stops 9, cylinders 10 and the hollow space in frame 3, with which a balancing and damping are provided, wherein all wheels 5 are held in optimal contact with the ground over which inline skate 1 travels. The obstruction caused by unevenness and obstacles in or on the ground is herein decreased. The remaining obstruction is limited in this embodiment to a quarter compared to a configuration without the invention.

[0026]FIG. 2 shows another embodiment of a means of transport according to the present invention, which is once again designed as inline skate 14. Inline skate 14 of FIG. 2 differs from inline skate 1 in FIG. 1 in a number of respects. The open connection formed through hollow frame 3 is thus sub-divided between different cylinders 10 of separate wheels using partitions 15. As regards the operation of the suspension, the wheels are sub-divided by partitions 15 into three sets. There are two sets each having two wheels, and one wheel is adjusted separately. This separate wheel is the rearmost wheel 5 as seen in the direction of forward movement of inline skate 14.

[0027] Apart from the rearmost wheel 5 in the direction of forward movement, all wheels 5 are suspended in the same manner in profiles 6, as shown with reference to FIG. 1. By arranging partitions 15 in hollow frame 3 the two front wheels 5 of inline skate 14 form a functional unit which operates in the same manner as the whole unit shown in FIG. 1, and the same is true for the third and fourth wheel, as seen from the front of inline skate 14 in the direction of forward movement thereof. The cylinders 10 associated with the first and second wheels 5 as seen from the front of inline skate 14 are thus in open mutual connection, but not with the cylinders of the other wheels. The choice for placing of the partitions 15 can be related to load zones. A rider of inline skate 14 will generally exert less force on the front wheels, so that also in the associated foremost part of hollow frame 3 a higher pressure of the fluid can be brought about therein. A different pressure can be brought about beneath the heel of a user or beneath the centre of the foot or shoe 2, since a greater force or load is exerted there.

[0028] Alternatively, the parts of the space in hollow frame 3 which are mutually separated by partitions 15 can be connected with for instance a throttle therebetween. This can be done through the partition 15, although a separate conduit can also be placed. This is not shown in the figures.

[0029] As already noted above, the suspension of the rear wheel 5 relative to the direction of forward movement differs from that of the other wheels 5. The tilt axis of this rear wheel 5 defined by pin 7 in slotted hole 8 is eccentric relative to the two cylinders 10 and displaced in forward direction relative to the position of this tilt axis in the other wheels 5. When a rider wants to stop, he need only lean back slightly in shoe 2 to bring about a substantial angular rotation of profile 6 of rear wheel 5. A brake block 16 is arranged behind rearmost wheel 5, so that in this backward leaning position of the rider shown in FIG. 2 a firm braking contact is realized between rear wheel 5 and brake block 16.

[0030] In FIG. 2 the foremost of the sub-divided spaces in hollow frame 3 is provided with a valve 17, with which fluid under pressure can be added or discharged so as to influence the rigidity of the balancing construction. The pressure is increased by feeding fluid under pressure. The other parts of the space in hollow frame 3 which is sub-divided by partitions 15 can also be provided with their own valve or similar measure for influencing or controlling the pressure of the fluid under pressure in the interior thereof. In the embodiment of FIG. 1 it is of course possible to suffice with a single valve. Types of connection other than a valve 17 are also possible.

[0031] It is noted that in the two embodiments explicitly described above, which both happen to relate to an inline skate 1, 14, each of the wheels is suspended independently. It will be apparent that the possibility of at least two of the wheels being arranged together on a sub-frame also falls within the scope of the present invention, wherein the sub-frame is tiltable on the tilt axis. A possible embodiment is one wherein the two front wheels are arranged on such a sub-frame just as the two rear wheels in the embodiment of FIGS. 1 and 2, while the middle wheel can still be suspended independently of the others. Such an embodiment results in a considerable reduction in the number of components, particularly cylinders and so on.

[0032] After examination of the foregoing, alternative embodiments will occur to the skilled person which all lie within the scope of protection as defined by the appended claims. Not all wheel suspensions therefore need necessarily also be tiltable in the direction of forward movement. When only a clearance away from and toward the frame would suffice for each of wheels 5 under the influence of the balancing construction, an embodiment of a means of transport can be equipped with a single cylinder per wheel. In an above described embodiment, wherein at least two wheels are suspended together in a single profile, wherein this single profile must be able to move up and downward away from and toward the frame, it is then still possible to suffice with a single cylinder, depending on other guide means, such as connections formed by pin 7 and slotted hole 8 for guiding such a sub-frame. As noted, use can also be made of a pneumatic system in addition or as alternative to a hydraulic system. The means of transport can have more or fewer than five wheels and, if desired, can even be applied in a cycle with only two inline wheels parallel to the direction of forward movement. Another embodiment is one wherein four wheels are used in two pairs, each comprising two inline wheels lying parallel to the direction of forward movement, and the pairs of wheels are situated at a mutual distance, such as in a wheelchair, a car, a cross-country vehicle and so on. In a favourable embodiment of the invention open connections are herein also provided back and forth between the balancing cylinders of the separate pairs of wheels. Thus achieved in the case of a vehicle such as a car is that, even when a bend is being negotiated, the bodywork on the frame designed as a body is held horizontal, while the wheels are pressed toward the frame on the inside of the bend and the wheels are pressed downward on the outside of the bend.

[0033] A known truck or lorry has independently suspended wheels particularly at the rear or under a semi-trailer. When driving over an obstacle, such as a speed ramp, one wheel at a time loses contact with the road surface. The frame twists and is thus damaged. This drawback will be effectively obviated by applying the invention here.

[0034] The invention can be implemented in a speedboat by assembling the hull from a number of segments which form the contact members and are displaceable up and downward relative to each other. Associated with each segment is a compartment, for instance a chamber filled with water, oil or gel, and the chambers in the segments are in open connection. If the hull passes over a wave in the water, it hull takes on the shape of the wave, wherein the segments adjust to the wave. The form of the wave is displaced through the hull as the latter sails over the wave. The resistance of the boat is decreased, and so it can travel faster at the same engine power. Such a boat will moreover not pitch onto the waves at high speeds, so it is possible to sail even faster without damage to the hull or the risk of the boat taking off out of the water and as it were lifting off out of control.

[0035] The cylinders used in FIGS. 1 and 2 can alternatively comprise plungers which do not directly undergo the action of the fluid, but via one or more than one enclosure forming the compartments for the fluid. During upward displacement the plungers press against the enclosure, and as a result of the displacement of the fluid round the enclosure other plungers are pressed downward. The fluid herein thus acts indirectly via the enclosure of the plungers designed as for instance a membrane.

[0036] It is thus apparent that within the scope of the present invention many alternative and additional embodiments are possible as well as those explicitly described in the foregoing. The invention is therefore limited only by the definitions thereof according to the appended claims, and the explicit embodiments as described above and shown in the figures serve only to elucidate such definitions. 

1. Means of transport, comprising: a frame; at least two contact members, such as skis or wheels, which are oriented parallel to the direction of forward movement and which are arranged with clearance away from and toward the frame hereon; and a balancing construction between the frame and the contact members for the purpose of preventing slanting of the frame, wherein the balancing construction comprises per wheel at least one compartment filled with fluid and the compartments of at least two of the contact members are in direct open mutual connection for the fluid.
 2. Means of transport as claimed in claim 1, wherein the contact members, the compartments of which are in open connection, lie in line.
 3. Means of transport as claimed in claim 1 or 2, wherein the compartments are hydraulic or pneumatic cylinders.
 4. Means of transport as claimed in claim 1, 2 or 3, comprising at least three inline contact members orientated parallel to the direction of forward movement.
 5. Means of transport as claimed in claim 4, wherein the contact members are sub-divided into at least two sets, wherein the compartments of the contact members are in open mutual connection in each of the sets.
 6. Means of transport as claimed in claim 5, wherein the open connections of at least two of the sets are additionally connected.
 7. Means of transport as claimed in claim 5, wherein in the compartments and the open connections of separate sets of contact members different pressures prevail in the fluid under pressure therein.
 8. Means of transport as claimed in any of the foregoing claims, wherein at least one of the contact members is arranged on the frame for tilting on a tilt axis lying transversely of the direction of forward movement, and the balancing construction of the relevant contact member comprises at least two compartments on either side of the tilt axis relative to the direction of forward movement.
 9. Means of transport as claimed in claim 8, wherein at least two of the contact members are arranged together on a sub-frame and the sub-frame is tiltable on the tilt axis.
 10. Means of transport as claimed in claim 8 or 9, further comprising a brake to be selectively energized, wherein at least one of the tiltable contact members energizes the brake when in tilted position relative to the direction of forward movement.
 11. Means of transport as claimed in claim 10, wherein the relevant contact member with which the brake can be energized is the rearmost wheel in the direction of forward movement.
 12. Means of transport as claimed in claim 10 or 11, wherein the relevant contact member with which the brake can be energized comprises a tilt axis placed eccentrically relative to the suspension cylinders, wherein energizing of the brake can be enhanced.
 13. Means of transport as claimed in any of the foregoing claims, further comprising at least one connection for feed or discharge of the fluid under pressure in order to selectively increase or decrease the height of the frame.
 14. Means of transport as claimed in any of the foregoing claims, wherein an elastically compressible body of for instance rubber is placed in at least one of the compartments or in the open direct connection.
 15. Means of transport as claimed in any of the foregoing claims, wherein the means of transport is one of the group comprising: roller skates, inline skates, wheelchairs, cars, cross-country vehicles, trucks, caterpillar vehicles, speedboats and so on.
 16. Balancing construction for use in a means of transport as claimed in any of the foregoing claims, comprising per contact member at least two compartments functioning on fluid under pressure, wherein the compartments associated with at least two of the contact members are in direct open connection for the fluid. 